All applicants must have their social media accounts set to 'public' to allow review by officials.
Consular officers will be looking for activity, posts and messages showing "any indications of hostility toward the citizens, culture, government, institutions, or founding principles of the United States," the department said.
The announcement is the latest step in the Trump administration's crackdown on international students, and the U.S. said applicants who refuse may have their applications rejected.